LOUISVILLE, Ky. (KT) – Much of Kentucky is under a heat advisory at least through Thursday, the University of Louisville and TreesLouisville released an updated urban heat mitigation study on Tuesday.
Residents are well acquainted with the challenges caused by urban heat, such as higher utility bills and serious health problems that disproportionately affect disadvantaged communities and residents with pre-existing health conditions. The initial foundational study commissioned in 2016 and co-authored by Brian Stone, a professor and director of the Urban Climate Lab at Georgia Institute of Technology, identified Louisville as having the fastest-growing urban heat island in the United States at that time.
Stone returned to Louisville in June 2026 to present the newest findings to Mayor Craig Greenberg, environmental researchers and community members. Louisville is the first city in the nation to have commissioned a follow-up study.
Aruni Bhatnagar, director of the Christina Lee Brown Envirome Institute at U of L, highlighted the organization’s mission and commitment to community-centered health research.
“We need to do things that matter in people's lives,” he said. “This study is one example of how our work can have a direct impact on the health of our community.”
Findings include:
Between 2016 and 2024, hot afternoon temperatures increased in about two-thirds of all neighborhoods in Louisville, with some neighborhoods experiencing a rise in temperatures exceeding 10°F.
In August of 2024, some neighborhoods were 20°F hotter on a typical hot day than other, more well-canopied neighborhoods.
If trees were added to 50 percent of the available spaces for tree planting in each neighborhood, high afternoon temperatures would fall by an average of 1.8°F, with some neighborhoods cooling by as much as 7°F.
The project, which used advanced climate models to generate highly detailed, hourly temperature maps for June, July and August 2024, offers an unparalleled view of where heat is most intense across Louisville's urban core. The study highlights areas where residents are most vulnerable to heat-related illnesses and where targeted urban forestry and greenspace strategies are most urgently needed to improve public health outcomes.
These insights will help guide tree planting initiatives by TreesLouisville and other partners, ensuring that efforts maximize cooling benefits.
For more detailed information on the study, visit the StoryMap that illustrates key findings.
